[Regulation of blood circulation in the extremities in intermittent claudication]. / A végtagi keringés regulációja claudicatio intermittensben.

UNLABELLED: The study was aimed to investigate the characteristics of the limb circulation in patients suffering from intermittent claudication. The study group consisted of 71 patients with intermittent claudication. As control served the data of 60 patients with intact peripheral circulation and 24 patients suffering from rest pain, too. The limb blood flow was measured by the venous isotope dye-dilution method. RESULTS: 1. The limb blood flow will be diminished in intermittent claudication already in resting state. The decrease of the limb blood flow is more expressed in severe claudication (with short claudication distance). 2. The pathological condition of the limb circulation in intermittent claudication can be characterized by the elevation of the limb vascular resistance. 3. The O2 consumption of the limb tissues will decrease in intermittent claudication. The data of the study are indicating that the regulation of the limb circulation will pathologically be changed in claudication. The reserves of the peripheral circulation are diminished and the insufficiency of the limb circulation will be manifested on walking.

The effect of vasodilator therapy on the limb circulation in hypertension.

The effect of vasodilator drugs on limb circulation was investigated in 59 hypertensive patients. Forty-six of them suffered from obliterative arterial disease, too. The drugs administered were: hydralazine, nitroglycerine and sodium nitroprusside. Isotope dilution method was employed to assess limb blood flow before and after acute treatment. Limb vascular resistance was calculated from the limb blood flow and the mean blood pressure. A marked increase in limb blood flow and decrease in vascular resistance following vasodilator treatment were observed in hypertensive patients suffering from obliterative arterial disease. No difference was found between the various vasodilators investigated. Normotensive patients with arterial disease exhibited the same response to a lesser degree. In exceptional cases, where blood pressure dropped abruptly, limb blood flow decreased and limb vascular resistance increased. The data show that vasodilator therapy in hypertension results in diminished limb vascular resistance and improved limb circulation in patients with obliterative arterial disease.

Examination of the effect of histodil prophylaxis in infarction patients with inhibited haemostasis.

The initiation of anticoagulants and drugs with platelet aggregation inhibiting properties is justified for the treatment of myocardial infarction in a great number of conditions. The well-known complications of this therapy are gastro-intestinal haemorrhage and the concomitant discomfort. In the period from 1983 to 1986 Histodil was given as adjuvant to therapy for infarction patients with ulcer, gastro-intestinal haemorrhage, hyperacidity or other epigastric burn-pain syndrome in history. The patients treated at our department between 1979-82 had not received Histodil for this purpose. According to the retrospective examinations the preventive effect of Histodil prophylaxis was 100%. Therefore the drug may be recommended to myocardial infarction patients in whom the inhibition of haemostasis means an increased risk of gastro-intestinal alteration.

The characteristics of the peripheral-limb-circulation in congestive heart failure.

The regulation of the peripheral-limb circulation was investigated in 21 patients suffering from chronic cardiac failure (NYHA stage II and III). In 11 patients the extremital circulation was intact, while 10 patients suffered from peripheral obliterative arterial disease, too (intermittent claudication or rest pain). The control group consisted of 75 subjects with normal cardiac condition. In 35 of the control subjects the peripheral circulation was intact, the remaining 40 suffered from extremital venous isotope dilution technique. In congestive heart failure the limb blood flow and the limb oxygen consumption slightly diminished, but remained in the normal range. The limb vascular resistance significantly increased. In patients suffering from intermittent claudication or rest pain, the marked diminution of the limb blood flow and elevation of the vascular resistance was more pronounced in congestive heart failure than in healthy subjects. The pathologically elevated limb vascular resistance decreased and the limb blood flow significantly increased in congestive heart failure on administration of vasodilator drugs. A pathological and mostly reversible increase in extremital vascular resistance is the most characteristic sign of the peripheral circulation in congestive heart failure.

The regulation of the cerebral circulation in long lasting bradycardia.

In the course of long lasting bradycardia in elderly patients, cardiac output will regularly diminish, circulation will slow down and signs of cerebral insufficiency may become manifest. The changes of cerebral circulation and its regulation were studied in 10 patients 61-74 years of age, with restricted cerebral regulatory capacity, suffering from permanent bradycardia. Cerebral blood flow was measured by using the venous isotope dilution technique by double punctures of the internal jugular vein. Hemispheric cerebral blood flow, cerebral O2 consumption and cerebral vascular resistance were determined during bradycardia and after termination of bradycardia by pacemaker. During long lasting bradycardia, cerebral blood flow and cerebral O2 consumption decreased, cerebral vascular resistance was elevated. After pacemaker implantation, cerebral blood flow and O2 consumption increased and cerebral vascular resistance decreased, approaching the normal value. The symptoms of cerebral insufficiency disappeared on improvement of the cerebral circulation.

Arteriovenous shunt-circulation in lymphoedematous limbs.

In lymphoedema of the extremities arteriovenous shunt circulation develops. Regulation of limb circulation was studied in 28 cases of (primary and secondary) lymphoedema by using the venous isotope dilution method and technetium-macroaggregate perfusion scintigraphy. As a result of lymphoedema, limb circulation (total limb circulation) increases, arteriovenous O2 difference is low and the O2 uptake of the tissues is normal. The development of arteriovenous (micro-, and macro-) shunts can be directly visualized by perfusion scintigraphy. In lymphoedema of the extremities the nutritive--capillary--blood supply of the tissues remains normal and therefore, no trophic disturbances develop. Lymphoedema is often associated with a fairly considerable arteriovenous shunt circulation and, in such cases, the cardiac output as well as cardiac performance are enhanced.

Arteriovenous shunts in peripheral lymphedema: hemodynamic features and isotopic visualization.

The hemodynamic characteristics of peripheral lymphedema were studied in 28 patients with uni- or bilateral leg swelling. Leg blood flow was measured by venous isotope dilution (a technique for nutritive--capillary blood flow) and arteriovenous shunts were visualized by perfusion scintigraphy using radiolabelled macroaggregated albumin. Arteriovenous communications were uniformly detected in lymphedema, with a calculated "shunt flow" of 200 to 600 ml/min. Other features in the lymphedematous leg included an elevated limb blood flow rate and narrowed arteriovenous oxygen difference.

Arteriovenous shunts associated with peripheral obliterative arterial disease. Haemodynamic, arteriographic and isotope studies.

From among 210 patients with severe peripheral obliterative arterial disease, the presence of an arteriovenous shunt was demonstrated in 17 cases. Arteriovenous communications were visualized by serial angiographic records and 99mTc macroaggregate isotope testing. The regulation of the limb circulation was investigated using the venous isotope dilution method. Characteristic haemodynamic changes were revealed in arteriovenous shunts associated with peripheral arterial obliterative disease: total limb blood was comparatively high, arteriovenous difference was low and limb O2 consumption was decreased. The clinical significance of the haemodynamic changes in arteriovenous shunting associated with obliterative arterial disease is discussed.

Effect of reconstructive surgery on the blood flow in the extremities. Early and late results.

The effect of vascular reconstruction on limb blood flow was studied in 20 patients with arterial disease in the lower extremity. Blood flow was determined with isotope dilution technique, ankle systolic pressure was estimated with the aid of Doppler ultrasounds. Circulation was studied prior to the operation (i); immediately afterwards (ii); 2-4 months later (iii); and 12-20 months later (iv). In obliterative limb arterial disease blood flow had remarkably slowed down with high vascular resistance in the limb. After surgery blood flow reached almost normal level and vascular resistance in the extremity also decreased to normal. Both the O2 uptake by the extremital tissues and systolic perfusion pressure in the ankle increased after the operation. At a later phase of the postoperative period blood flow in the limb slightly decreased but even after a year it was greatly improved and vascular resistance was much less as compared to the state before reconstructive vascular surgery.

Effect of ethyl apovincaminate on the cerebral circulation. Studies in patients with obliterative cerebral arterial disease.

The effect of ethyl apovincaminate (RGH-4405, Cavinton) on the cerebral and systemic circulations has been studied in detail in ten cases of cerebrovascular disease. 10 mg doses of Cavinton were given as infusion within 4-6 min; circulatory tests were carried out prior to administration of the drug and 3-6 min after. The principal results showed the following: On Cavinton cerebral vascular resistance was strongly reduced, while cerebral fraction of cardiac output significantly increased. On acute effect of the drug arterial mean pressure slightly decreased but cerebral blood flow nevertheless increased in general. Total vascular resistance also decreased but this decrease was less marked than that registered in cerebral vascular resistance.

Effect of the carotid sinus nerve stimulation on nutritive myocardial blood flow in regional cardiac ischaemia.

The authors have studied the local blood flow regulation of the heart under the influence of the stimulation of the carotid sinus nerve in segmental myocardial ischaemia. The experiments were carried out on 38 dogs. By ligating the mid-portion of the left anterior descending coronary artery, a small artificial infarction has been produced. Circulatory examinations were made after 24 hours following the coronary ligation. In 18 dogs the circulatory investigations were done during the electrical stimulation of the carotid sinus nerve while 20 dogs were used as control. The local nutritive blood flow of the heart was measured by the administration of 86 rubidium in the intact zone, in the ischaemia (necrotic) zone and at the border zone of the heart. According to the experimental data, under the influence of the carotid sinus nerve stimulation the blood flow of the intact zone does not change considerably while the necrotic and border zones increases to a great extent. Reflex redistribution of the myocardial blood flow probably plays a decisive role in the antianginal effect of carotid sinus nerve stimulation.